The error may be slight, but it's an error nonetheless, Stephen Hughes said.

Dr Hughes claims he has discovered that the dictionary's definition of the word "siphon" has been incorrect since 1911.

The definition in the Oxford English Dictionary, and many other dictionaries, stated that atmospheric pressure was the force behind a siphon.

But in fact it is the force of gravity at work.

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"It is gravity that moved the fluid in a siphon, with the water in the longer downward arm pulling the water up the shorter arm," Dr Hughes said.

When Dr Hughes stumbled across the mistake he alerted the dictionary's revision team, which had just completed revising words beginning with the letter "R".

"I thought, 'Oh good, just in time,' because S is next," he said.

The senior lecturer in physics discovered the error after viewing an enormous siphon in South Australia, transferring the equivalent of 4000 Olympic swimming pools from the Murray River system into the depleted Lake Bonney.

"I thought this example would make a great education paper ... but in my background research I discovered there was much contention about the definition of the word 'siphon'," Dr Hughes said.

"I found that almost every dictionary contained the same misconception that atmospheric pressure, not gravity, pushed liquid through the tube of a siphon."

The Oxford English Dictionary now defines a siphon as: "A pipe or tube of glass, metal or other material, bent so that one leg is longer than the other, and used for drawing off liquids by means of atmospheric pressure, which forces the liquid up the shorter leg and over the bend in the pipe".

The dictionary's review team has agreed to re-examine the definition.

Dr Hughes is now determined to set the record straight, and says the issue should not be taken lightly.

"We would all have an issue if the dictionary defined a koala as a species of bear, or a rose as a tulip," he said.

He has now turned his attention to dictionaries in other languages.

"I would like to know if the siphon misconception exists in dictionaries in other languages, and also if there are incorrect definitions of siphon in school text books," he said.